Abstract

Five rice paddy soils located in southwest China were selected for geochemical and microbial community analysis. These rice fields were irrigated with river water which was contaminated by Fe–S-rich acid mine drainage. Microbial communities were characterized by high-throughput sequencing, which showed 39 different phyla/groups in these samples. Among these phyla/groups, Proteobacteria was the most abundant phylum in all samples. Chloroflexi, Acidobacteria, Nitrospirae, and Bacteroidetes exhibited higher relative abundances than other phyla. A number of rare and candidate phyla were also detected. Moreover, canonical correspondence analysis suggested that pH, sulfate, and nitrate were significant factors that shaped the microbial community structure. In addition, a wide diversity of Fe- and S-related bacteria, such as GOUTA19, Shewanella, Geobacter, Desulfobacca, Thiobacillus, Desulfobacterium, and Anaeromyxobacter, might be responsible for biogeochemical Fe and S cycles in the tested rice paddy soils. Among the dominant genera, GOUTA19 and Shewanella were seldom detected in rice paddy soils.

Notes

Acknowledgments

This research was funded by the National Basic Research Program (2014CB238903), the National Natural Science Foundation of China (41173028), and the Opening Fund of State Key Laboratory of Environmental Geochemistry (SKLEG2013810). We thank Ying Huang for her suggestion and help for CCA analysis. Associate editor Dr. Akira Kimura and two anonymous reviewers are acknowledged for critical comments and suggestions, which have improved the manuscript considerably.